US Patent 6843059 Combustor inlet diffuser with boundary layer blowing

A gas turbine engine combustor inlet diffuser assembly has at least one diverging annular wall including a flowpath surface bounding a diffuser flowpath. An annular blowing slot is axially located along the annular wall and an annular blowing air flowpath leads to and is in fluid communication with the blowing slot. An annular array of scoops disposed in the diffuser flowpath downstream of the blowing slot have upstream facing openings and are in fluid communication with the blowing air flowpath. The annular scoops are supported on hollow struts. Each of the hollow struts has at least one radially extending flow passage for directing blowing air from the scoop to the blowing air flowpath. The blowing slot opens in a downstream direction with respect to the diffuser flowpath. A row of blowing air compressor blades disposed across the blowing air flowpath may be used to pump up the pressure of the blowing air.